Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/38—Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel
  • H02J3/40—Synchronisation of generators for connection to a network or to another generator
  • H02J3/42—Synchronisation of generators for connection to a network or to another generator with automatic parallel connection when synchronisation is achieved
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D9/00—Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby; Wind motors specially adapted for installation in particular locations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D9/00—Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby; Wind motors specially adapted for installation in particular locations
  • F03D9/10—Combinations of wind motors with apparatus storing energy
  • F03D9/11—Combinations of wind motors with apparatus storing energy storing electrical energy
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
  • H02J3/1885—Arrangements for adjusting, eliminating or compensating reactive power in networks using rotating AC generators, e.g. synchronous generators
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
  • H02J3/1892—Arrangements for adjusting, eliminating or compensating reactive power in networks the arrangements being an integral part of the loads or of their control circuits
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/38—Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K37/00—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors
  • H02K37/10—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
  • H02P9/42—Arrangements for controlling electric generators for the purpose of obtaining a desired output to obtain desired frequency without varying speed of the generator
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D12/00—Bipolar devices controlled by the field effect, e.g. insulated-gate bipolar transistors [IGBT]
  • H10D12/01—Manufacture or treatment
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/72—Wind turbines with rotation axis in wind direction
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/76—Power conversion electric or electronic aspects
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
  • Y02E40/30—Reactive power compensation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
  • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin

Definitions

• the invention comprises a method for operation of a permanent magnet synchronous machine as stated in the introductory part of claim 1, and a device as stated in the introductory part of claim 6, in an electric system comprising one or more such machines.
• the magnetizing machine provides collector less transfer of the magnetizing current.
• the auxiliary motor is running the machine to synchronous rotation. It is possible to combine the magnetizing machine and the starting machine as described in PCT application WO 85/02886. In current PMSM systems converters is normally used for connecting the machine to the net.
• the converter provides a decoupling between net and machine which allows operation at variable rotation.
• the converter allows control toward the net.
• This "active front end” may use switches instead for diodes toward the net.
• This configuration provides a currently satisfactory net connection.
• the drawback is the increased costs by the converter. In some cases the costs for the converter equal the machine costs.
• PMSM machines On slow rotating machines, normal synchronous machines will require unsuitable large diameter to accommodate the magnetizing windings. In such cases a permanent magnet synchronous machine is a favorable alternative.
• the drawback of PMSM machines is that the field cannot be controlled with a field winding, the control needs converters.
• PMSM machines are connected directly to the net and are operated as motor or generator. This configuration may be used in a system with a stable speed. Due to the fixed voltage/speed curve of the PM machine, the flow of reactive power flow cannot be controlled in such systems.
• An alternative control for such systems is to install a parallel source of reactive power. Such sources can be established with staged static condensers or switched condenser assemblies (STATCOM). The drawback of such systems is the high costs.
• Soft Starter is a notion used for systems with devices for providing a better start I regard of start current and transient torque (Design of Intelligent Soft-Start Controller for Induction Motor, Wen-Xiong Li, Jian-Guo Lv, Ming-Sheng Lw.
• the main object of the invention is to reduce costs and size, with a machine occupying less space than a corresponding permanent magnet synchronous machine. It is also an object to provide a system with a higher efficiency compared with system with full converter.
• the method according to the invention is described in claim 1. It is based on double feeding of the stator of a permanent magnet synchronous machine.
• the double feeding is achieved by using the combination of a direct feeding and a converter feeding of a stator.
• This provides more advantages compared to prior art technology.
• the advantages of different machine types are stated more specifically in the following examples.
• the invention may be called "double fed permanent magnet synchronous machine" (DFPMPS).
• the invention also comprises a device in an electric system including a permanent magnet synchronous machine, as stated in claim 6. It comprises a device in a system with a permanent magnet synchronous machine, such as a motor or a generator, with a converter for feeding or withdrawal of power, the novelty being the converter being provided to feed or withdraw a power substantially under the maximum power, to combine direct feeding and converter feeding (or withdrawal).
• a permanent magnet synchronous machine such as a motor or a generator
• the converter may be rated for less than approximately 50% of the total power (nominal power).
• the invention may be used at different permanent magnet machines, both rotational and linear, motors as well as generators.
• Permanent magnet synchronous machines today are thus connected direct to the grid or connected over a full converter (with the nominal power of the machine).
• By combining both kinds of connection of the stator it is possible to have a solution operating on constant velocity with control of the reactive power flowing.
• the difference between the prior art and the novel solution is the double feeding of the prior art systems, feeding stator direct and the rotor via converter, while the novel invention has a feeding with both methods (direct and converter) to the stator.
• the rotor of a PMSM system has permanent magnets.
• the novel system has reduced costs compared to a full converter solution, but will provide a substantial part of the functionality. Additionally to controlling the reactive power feeding, the converter may be used for controlling the torque. This novel solution has no brushes or collector rings and will thus need substantially less maintenance than prior art systems (Double Fed Induction Generator - DFIG).
• the size of the converter fed part will vary according to the requirements for control of the system.
• the requirements for coupling varies from country to country. In Norway, the proprietor of the grid is placing the requirements.
• systems larger than 10 MW have particular connection requirements.
• the requirement for the converter fed part of the system reach 50%.
• the invention will make the system more resistant to malfunction of the system.
• the system may deliver reactive power to the grid.
• the requirements of the grid proprietor will not guide the system design.
• the requirement for stable voltage will be most important. If one or more generator systems provide a voltage changes or frequency changes exceeding the limits for the output quality, the power supplier will be responsible for possible damage to the electric system. At the consumer side, damage occurs to equipment normally when the voltage is too high or too low.
• DFPMSG Direct fed permanent magnet synchronous generators
• the terminal voltage of the generator system is controlled, to avoid damages at the consume side.
• the converter to be used according to the invention may be a standard converter. There is no limitation to the type of switches or topologies to be used. One example may be a full bridge converter. This converter may be based on IGBT (Insulated Gate Bipolar Transistor) technology and be designed with a part for the grid side (Active Front End) and a part connected to the motor. Said two converter parts are typically connected with a DC connection.
• IGBT Insulated Gate Bipolar Transistor
• Rl, R2, Sl, S2, Tl, and T2 denotes windings connected to two separate zero points. The windings are grouped to make each group a three phase system.
• Group 1 consists of Rl, Sl, Tl.
• Group 2 consists of R2, S2, T2.
• the group 1 is connected to the grid through a converter 3.
• Group 2 is connected direct to the grid through a grid connector 2. When the machine is started the rotor is accelerated with the converter 3. It is possible to use the converter controlled part for operating at changing speeds. This may be useful in a wind power system when withdrawing a reduced power at low speeds. Or in a propeller system with pitch control.
• 1 denotes the connector between the direct connection and the converter. It may contain grid filters and/or transformers.
• Figure 2 a system is shown with two machines on the same shaft. This principle can also be used in systems without a common shaft for starting an engine with an alternative admission (e.g. water or steam).
• an alternative admission e.g. water or steam.
• Figure 3 1 denotes the connector between the direct connection and the converter. It may contain grid filters and/or transformers.
• a connector for making a direct connection denotes a connector for making a direct connection. It may be physical (a contactor) or electronically (power electronics)
• the converter of Figure 3 may be a common full bridge converter or another converter concept, e.g. a multi level converter. Converters with switches to be independently disconnected are favorable, e.g. IGBT switches.
• the converter is connected over the direct connection via a filter or grid transformer.
• the filter may be L or LCL for this kind of system.
• the rating of the filter together with the converter will govern the part of the power to be controlled.
• the reactive and the active power may be controlled.
• the system may also be controlled without disturbance of the grid. If only the direct connection is used, maximum efficiency may be achieved for some operations.
• the last solution is optimal in regard of efficiency, as the system may deliver full power without using the converter.
• the converter mode of operation may be changed between passive, synchronizing, starting, stopping, reactive compensator and more.
• Figure 4 shows an alternative to the electric system of Figure 1.
• 1 denotes the stator of the electric machine (6 phase)
• 2 denotes the device for connection to a grid
• FIG. 4 is a schematically illustration of a double fed stator.
• the stator 1 has 6 phases. Three of the phases are connected to the direct connection 3, while three of the phases are connected to the converter 4. Both supplies are connected to the grid 5 to have the stator double fed. Additionally the system may also have filters and transformers. Contactors may be arranged to allow by pass and/or parallel connection of the converter.
• Figure 5 is showing an alternative connection of the double fed system.
• the converter is connected between the two separate sets of windings.
• Figure 6 is showing a possible connection for the converter in Figure 5.
• the configuration in Figures 5 and 6 will allow all advantages of a double feeding (start, braking, reactive power control, damping of transients etc. )
• the system may be structured differently: Integrated solution
• a machine may be split in different groups of windings. Each group is representing a three phase connection. One or more groups may be direct fed, while one or more may have a converter connection. An electric machine may be arranged with multiple three phase systems, e.g. a 9 phase system, with 3 phases connected via a converter and 6 phases connected direct.
• the system control may be provided to control the power flow through the converter and the physical admission. Examples of use
• the invention may be used at a generator system powered by water or other kinds of energy.
• the system is operating like prior art synchronous machines with an auxiliary machine to achieve synchronous speed.
• the difference is the use of double fed windings of a stator of a PM machine.
• An example of this kind of system may be the propulsion system of a ship.
• the propellers are having a constant speed and adjustment of the deflection of the propeller blade.
• This type of system may be started with propellers of zero deflection with the converter and some of the windings. When the machine has a synchronous speed, then the part to be direct connected is engaged. In this way less expensive and more efficient propulsion is achieved.
• a further version of this invention is used for double fed linear PSM machines. Generally this may provide the same advantages as described for rotating PMSM machines. This is further described with an example.
• Linear machines are used in different markets and applications.
• One example is linear systems with a spring in each end, wherein resonance is involved. Such resonance systems are used for multiple applications. Common to some of these applications is the need for accelerating the system to the resonance velocity. When this velocity is achieved, the work or operation is conducted at this velocity.
• the invention with double fed stator may e.g. be used at linear machines with a frequency converter for starting. At the resonance frequency, the double fed windings are connected. The converter fed windings may provide control to the machine, together with control of the reactive power against the grid.
• Double feeding with full direct connection A further alternative of a double fed PMSM may use the system of Figure 3, showing an alternative double feeding of the stator.
• the stator is also fed by a converter and a direct connection.
• the novel system may operate independently
• the active power can be controlled at substantially lower costs
• the reactive power can be controlled at substantially lower costs - It is possible to change between direct and converter feeding ( Figure 3) -
• the invention may be used with multiple stators on a common shaft
• the invention may be used in systems with multiple machines, where one machine is converter fed and the remaining direct fed
• Double feeding may be used for lowering the losses.
• the invention allows the replacing of a normal synchronous machine with a double fed permanent magnet synchronous machine.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Control Of Eletrric Generators (AREA)
• Motor And Converter Starters (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

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Family Applications (1)

Country Status (7)

Cited By (2)

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Citations (7)

Family Cites Families (3)

• 2008
  • 2008-12-19 NO NO20085321A patent/NO329244B1/no unknown
• 2009
  • 2009-12-16 KR KR1020117016858A patent/KR20110104063A/ko not_active Ceased
  • 2009-12-16 ES ES09836438.3T patent/ES2687796T3/es active Active
  • 2009-12-16 WO PCT/NO2009/000436 patent/WO2010077145A1/en not_active Ceased
  • 2009-12-16 EP EP09836438.3A patent/EP2374192B1/en active Active
  • 2009-12-16 CN CN2009801559710A patent/CN102318156A/zh active Pending
• 2011
  • 2011-06-16 US US13/161,819 patent/US20110309805A1/en not_active Abandoned

Patent Citations (7)

Non-Patent Citations (3)

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